PVC Membrane Cesium Ion-Selective Sensor Based on Cephalexin Antibiotic

Abstract

Cephalexin antibiotic {5,6,7,8-tetrahydro-8-thioxopyrido [4′,3′,4,5] thieno [2,3-d] pyrimidine-4(3H)one} (TTPTP) is used as a novel ionophore in plasticized PVC matrix membrane sensor for cesium ion. The sensor displays a rapid and linear response for cesium ion over the concentration range 1.0 × 10⁻¹–3.0 × 10⁻⁵ mol L⁻¹ cesium ion with a Nernstian slope of 60 mV decade⁻¹. The sensor response is stable for at least one month and exhibits good selectivity for cesium ion over many alkali, alkaline earth, and transition metal cations. The sensor is used over the pH range 4.5–10 and is successfully employed for the determination of cesium in aqueous and partially nonaqueous medium.

Keywords:

• Cesium sensor
• Potentiometry
• PVC membrane
• Cephalexin antibiotic